1. Technical Field of the Invention
The present invention relates generally to an automatic toll collection system designed to automatically collect tolls through radio communication between an electronic toll paying unit installed in a vehicle and a toll collecting unit installed in a toll booth on a roadway, and more particularly to a radio-based electronic toll collection system having a security monitor for monitoring abnormalities of an electronic toll paying unit and a toll collecting unit.
2. Background of Related Art
Japanese Patent First Publication No. 49-98300 teaches an automatic toll collection system designed to collect tolls from each vehicle moving along a toll road automatically through radio communication between an in-vehicle unit and a communication facility installed on the road. If such a system malfunctions, a large amount of time is required to troubleshoot the system, thus resulting in traffic congestion around a toll booth.
It is therefore a principal object of the present invention to avoid the disadvantages of the prior art.
It is another object of the present invention to provide an improved automatic toll collection system capable of troubleshooting an electronic toll paying unit installed in a vehicle and/or a toll collecting unit installed in a toll booth.
According to one aspect of the present invention, there is provided a system for automatic collection of tolls from a vehicle moving along a roadway which comprises: (a) a toll collecting facility installed on the roadway, the toll collecting facility collecting the tolls from an in-vehicle unit installed in the vehicle through radio communication with the in-vehicle unit; and (b) an inspecting facility inspecting the in-vehicle unit when an abnormal condition in which it is impossible to collect the tolls from the in-vehicle unit correctly is encountered, the inspecting facility being located outside the roadway.
In the preferred mode of the invention, the toll collecting facility determines whether the abnormal condition is encountered or not through radio communication with the in-vehicle unit.
A guidance unit is further provided which provides a guidance signal to the in-vehicle unit for leading the vehicle to the inspecting facility when the abnormal condition is encountered.
An image pickup sensor and a gate are further provided which are installed on an automatic toll collection lane mounted on the roadway. When a driver of the vehicle takes action to open the gate, the image pickup sensor picks up an image of the vehicle and the driver.
The inspecting facility includes a testing unit which locate an abnormality of the in-vehicle unit through radio communication therebetween.
The inspecting facility compares a result of inspection of the in-vehicle unit with determination of whether the abnormal condition is encountered or not made by the toll collecting facility to determine whether the abnormal condition is caused by the in-vehicle unit or the toll collecting facility.
A means is further provided which determines whether the abnormal condition is encountered or not prior to communication between the in-vehicle unit and the toll collecting facility. When it is determined that the abnormal condition is encountered, the means leads the vehicle to the inspecting facility.